Separable fastener element and the method of making the same



June 11, 1940. L, MQRgN ET A 2,203,694

SEPARABLE FASTENER ELEMENT AND THE 11:51am). OF MARINGTHE SAME Filed Feb. 15, 19 37 2 Sheets-Sheet 1 ATi'oRNE June 11, 1940. 1.. H. MORIN El AL SEPARABLE FASTENER ELEMENT AND THE METHOD OF MAKING THE SAME Filed Feb. 15, 1937 2 Sheets-Sheet 2 INVE 101/0 0/4145 Mfl/F/A/SAY BY f Patented June1l,1940

PATENT orrlcs SEPABABLIJ. FASTENEB ELEMENT THE METHOD OF MAKING THE SAME Louis B. Morin andDavls Marlnsky, Bronx, N. Y., assignors to Whitehall Patents Corporation. New York,.N. Y., a corporation of New York Application February 15, 1937, Serial No. 125,830

4 Claims.

This invention relates to the manufacture of links or scoops of separable fastener stringers as well as the sliders and other parts of devices of this kind; and the object of the invention isto 5; provide devices of the kind and class referred to formed from an insert or reinforcement enveloped or substantially enveloped in a body of nonmetallic material forming a coating .or jacket therefor to give to the device distinct and varied 10. color values and to form a protection for the inr so strength and other advantageous characteristics of this material and the fact that it may be produced in many colors; a further object being to provide a method which consists in first attaching an insert or reinforcing member to a supporting g5 strip or strand and then enveloping said insert in an outer shell or jacket; a still further object being to provide a novel method of supporting an insert in a casting or molding die in the process of casting an enveloping casing or jacket on the SQ insert to insure proper and even distribution of the material employed in the Jacket around said insert, which method is applicable to the die casting ormolding of any kind or class of device including a reinforcement insert; and with these in a device of the class described and the method as more fully hereinafter specifically described and claimed. i The invention is fully disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts of the improvement are designated by suitable reference characters in each of the views, and in which:

Fig. 1 is a diagrammatic side and sectional view of a part of a separable fastener stringer indicating the methodof forming the links thereon.

Fig. 2 is a. diagrammatic transverse sectional view through the die shown in Fig. 1, illustrating 'the method of supporting the insert in the impression of the die in theoperation of casting therearound. l mFig. 3 is a sectional view on the line 1-3 of and other objects in view, the invention consists Fig. 4.13 a perspective view of one of the link inserts detached.

Fig. 5 is a sectional plan view diagrammatically illustrating another f form of die employed for casting the slider.

Fig. 6 is a section substantially on the line 6-6 of Fig. 5.

Fig. 7 is a perspective view of the finished slider, detached, formed from the dies shown in Figs. 5"and 6.

Fig. 8 is an enlarged sectional detail view of a part of the modification shown in Fig. 6.

Fig. 9 isa view similar to Fig. 8 showing parts in a different position at the completion of a casting operation. 15

Fig. 10 is a view similar to 5 diagrammatically illustrating the method of forming another "form of slider. a

Fig. 11is a section substantially on the line ll-ll of Fig. 10; and, v Fig. 12 is a perspective view showing a slider made from the dies shown in Figs. 10 and 11.

Heretofore, in the construction of the various parts of separable fasteners such as the links or scoops, sliders, end stops, Pulls and the like, these parts have been either formed from sheet metal stampings or of unitary cast or molded bodies. It is the object of the present invention to form parts of. the kind under consideration from an inner core piece or insert composed of 3j0 one material around which is formed by molding, die-casting or otherwise, an enveloping casing or jacket which envelops all or substantially all of the insert, either for the purpose ofapplying a hard shell or outer surface to a softer inner insert part or in providing a more rigid, sturdy reinforcing member as an insert within a plastic outer casing or jacket especially in enveloping a metallic part in a casing or jacket of cellulose acetate or similar thermoplastic material, and still more particularly in molding or die casting such material around the insert in the formation of separable fastener devices of the kind under consideration.

Another'distinctive feature of the present in- 45 vention resides in a novel method of supporting and backing" an insert within the impression chamber of a die so as to maintain the insert in proper position within the impression in resisting the pressure of the castingmaterial injected into the impression and during the casting operation to automatically relieve said supporting and backing means to provide a complete or substantially complete envelopment of the insert within the body of cast material. While in the present illustrations, this result is accomplished in conjunction with a core which is utilized as a means of ejecting and feeding the cast body from the impressions of the die, in many instances, the use of such a core is not essential.

A still further distinctive feature of the invention resides in the process which consists in applying one part or element to a supporting tape or strand and arranging a number of said parts at spaced intervals thereon and then casting or otherwise applying the outer coating, casing or jacket to said parts, for example, in first applying a number of metallic links to the stringer tape of a fastener stringer and then applying the cellulose acetate jacket to the metallic links in a successive series of casting operations.

In Figs. 1 to 4 inclusive, the invention is shown as applied to the manufacture of the stringer tapes of separable fasteners, and in these figures, I5 represents a part of a stringer tape having a beaded edge IE to which is attached at equally spaced intervals a plurality of scoops or links I].

The links Il may be formed in any desired manner to provide beyond the beaded edge the coupling end portions having sockets l8 at one side and the projecting members l3 at the other side for engaging sockets of opposed stringer links. In the construction shown, the links ['1 are in the form of die castings. In forming these links, opposed side surfaces are provided with elliptical orjother recesses 20 having relief grooves 2| at one end thereof opening through the outer surfaces of the link and the inner surface of the groove 20 as clearly seen in Figs. 3 and 4 of the drawings.

In the drawings, we have diagrammatically illustrated a process of molding or die casting a coating, casing or jacket 22 of plastic material around the link I! to completely cover all exposed surfaces thereof with the exception of the sockets or recesses l8 in which the core and ejector pin 23 is supported during casting operation. This pin is disposed between adjacent surfaces of die parts 24, 24a within and between which is formed an impression 25 sufliciently great in size and contour so as to form a clearance space between the link "which forms an insert piece on the walls of the impression to provide on the insert at the completion of a casting operation a coating, casing or jacket of predetermined or desired thickness throughout.

In the construction shown, the thickness is illustrated as being substantially even on all surfaces, but it will be apparent, however, that in some instances the thicknesses may vary to supply an added amount or a decreased amount of the coating material to suit the use to which the device is intended. On the parting line of the dies and between adjacent surfaces thereof is formed an opening or passage 26 forming a gate of communication between the impression 25 and the ejection nozzle 21 adapted to be moved into position to register with the passage 26 in the intermittent casting operations to be performed. In using cellulose acetate as a casting material around the insert link I! in forming the jacket 22, it is desirable to provide means for backing up and supporting the insert against movement within the impression 25 so as to resist the excessive pressures required to introduce the casting material into the impression. For this purpose, two supporting or backing pins or members 23, 28a are arranged in each of the die parts 24, 24a, and the inner ends thereof are a'dapted to seat in the recesses 20 of the links or inserts II. The

pins or to hold said pins seated in the recesses 20.

In the operation of carrying out the process diagrammatically illustrated in Figs. 1 to 3 inclusive, a stringer i5 with the links or'elements I1 spaced thereon is arranged in position to move between adjacent surfaces of the die parts 24, 24a or between the parting line thereof, and suitable means such as indicated at 33 in Fig. 3 of the drawings is provided for normally supporting the element I! in the angular position shown in said figure in order to clear the core pin 23. The stringer is then arranged in positionto dispose one end link or element I! in position between the parting line of the dies and below the means 33. The pin 23 is then moved downwardly and the dies brought together, and at the same time, the pins 23, 23a are moved into the recesses 20 of the element l1 and said element is then supported within the impression 25 of the die. When the die parts are in firm engagement with each other and held so under pressure, the casting materialis forced into the impression forming the casting 22 around the element II as before described. In this operation, the pressure of the casting material extending into therelief grooves 2i to the bottom wall of the recesses 23 and beyond the inner surfaces of the pins 23, 23a will operate to automatically force the pins 23, 28a outwardly against the adjustable tensional means 32, 32a until these pins strike the stop shoulders 34, 34a, in which position, the inner surfaces of the pins will be in substantial alinement withthe boundary walls of the impression 25 and the resulting casting will thus have smooth or relatively smooth and continuous outersnrfaces, the' definition of which will be defined by the last named position of said pins 28, 23a. In other words, no recesses will appear where the recesses 20 were provided in the element I'I. Water or another cooling agent will be circulated through passages 35 formed in the die parts to aid in chilling the casting.

At the completion of the casting operation, the die parts 24, 24a are separated sufliciently to free the casting from theimpresslon in each die part, but before completely separating the die parts; the pin 23 is raised to remove the same from the casting and out of engagement with the next link or element l1. Then, suitable means, not shown, is provided for feeding the tapeli downwardly to bring 'said next link in position to enter the impression of the dies and the above operation is repeated.

As the castings are formed and removed from the dies' or at any desired point'therebeyond, the projecting gates 36 of the casting may be trimmed off by asuitable e or other trimming tool 31 as indicated at the lower part of Fig. 1 of the drawings. Any other trimming or finishing operations that may be necessary can be performed. In some instances, it may be desirable to chill the links or elements immediately prior to insertion into the impressions of the die in order to increase the setting or hardening operation of casting or molding materials employed, whereas, in other cases, the normal temperature of the link or element'will be sufficient and desirable in performing the desired casting operation thereon.

In the above described casting. operation, in

aaoaoac initially injecting the casting material into the.

impression 25, a relatively low pressure may be employed, and this pressure increased duringthe final stages and especiallythe stage wherein the pins 26, 26a are forced outwardly. The pressure of the casting material which is of a nature to remain plastic for an appreciable period of time permit this plastic material to exert hydraulic pressure against the inner. surface of said, pins in forcing the same outwardly. In this connection, it will be understood that normally such actions might not take place with casting. ma-

thereof an elongated loop 40 for the attachment of a finger piece or pull thereto. The other wall 4| of the slider joins the'wall 39 in a V-shaped web42 indicated in Fig. 6 of the drawings as in other devices of this kind. In this construction,

a slider blank is first formed from a. die cast body and the side edges 43 of this blank are straight or unbent. This blank forms the insert to be disposed within an impression 44 formed between adjacent die parts 45, 45a andsupported upon .a pin 46 arranged on the parting line of the die parts and also by resilientlycontrolled backing and relief pin units 41 and flasimilar in all respects to the units consists of the pins 26, 26a

and the parts associated therewith, as specifically described in connection with Figs. .1 to 3 in elusive. For this reason, further. detailed description of these units is unnecessaryin Fig.. 6.

The units 41, 41a are arranged substantially on the parting line, sufllciently off-centre, however,

to retain the pins against displacement from the die parts. However, suitable means may be provided for supporting the pins on the parting line,

it being understood that the spring actuated arms maybe offset or angularly disposed. These units 6 mayalso bemounted as disclosed in Fig. 2, where the pins 26, 28a are at right angles to the parting line, or, in fact, may be arranged in any desired position, depending entirely upon the contour of the insert and the desired location of the supports with respect to the material introduced into the impression. e

by-pass grooves 49. 49a as clearly represented in,

The top wall of the part 46 and the outer surfaceof the bottom wall 4| of the slider are recessed asseen at 46, 48a to receive the pin parts of the units 41, 41a. These recesses also have the Figs. 8 and 9 of the drawings, in which figures, the movement and operation of the units 41, 41a are clearly illustrated on an enlarged scale. The

position of the unit "a in Fig. 8 is just prior to v the applied pressure, and in Fig. 9 shows the result of the applied pressure and the finished wall .of the cast body 56 completely covering the recessed part 48a. of the insert 36. The illustration in Figs. 8 and 9 is applicable to the structure shown in Figs. 1 to 3 inclusiveto clearly illustrate the backing and relief pins.

Between the parting line of the dies 45, 45a is an admission opening or gate 5| so that the plastic material forming the casing or jacket enveloping the insert 36 may be injected into the impression 44 from an injectornozzle 52. The

gateformed by the passage 5i may be trimmed oil in any desired manner after the device has been formed.

, With the construction shown in Figs. 5 and 6, after the pins have moved into the position shown in Fig. 9, the die parts 45, 45a are separated and the core pin 46 is used to eject the casting from the impression 44 in this operation and also to feed the casting out of registering position with the impression and this casting may be stripped from the core 46 and another insert 38 applied thereto and the above'casting operation may be repeated. d

After the castinghas been formed in the manner above stated, the side edges 43- of the slider are still straighter flat. The next operation in finishing the slider, aside from any trimming operations which may be necessary will consist in bending the side edges inwardly to form intumed flanges 53 at opposite sides of the finished slider as shown in Fig. 7 of the drawings and between which are the usual passages 54 for receiving the tape of the stringer, such for example, as the pression 51 between the die parts 56, 58a. With a this method, in addition to the core and ejector pin 59, a supplemental core and supporting pin 60 is employed and substituted for the pin 'units 41 and 41a. With this construction the pin or reduced end 6| thereof is arranged in the aperture 62 of ,an upwardly projecting lug 63 on the top wall of the slider 56.

With this construction, the impression 51 is so formed as to not extend onto the lug 66 sothat after the cast body, 64 has been formed on the core, the outer surfaces of 'the lug 63am not covered or coated with said material. In other words, the pin 60 is disposed in the die part 58 at one side of the'impressibn 51. with this method, after the casting 64 hasbeen formedby introducing the material through the gate 65 from the nozzle 66, the die parts 58, 58a are separated and the pin 66 withdrawn. The core 59 is here also used to eject the casting from the impression 5land when the casting has been removed from the dies, the same is stripped from the core and the next casting operation is .performed. With this construction, the location of the pin 66 in conjunction with the core 59 will centralize the slider core within the impression 56 with respect to the top and bottom walls, whereas the shoulder .601: on. the pinengaging the lug 63 will support the slider, in conjunction with the core 59,'in proper position in the other direction in the impression 51 as clearly illus-. trated in Flg.'10 of the drawings. After the casting has been formed from the dies in the manner illustrated in Figs. 10 and 11, the edges of the side walls are turned inwardly as indicated at 61 in Fig. 12 of the drawings, as with the construction shown in Fig. 7, and the trimming and other finishing operations are performed thereon.

While the invention has been shown as applied to the making of separable fastener links and .sliders employed for coupling and uncoupling the links, the invention is also applicable to the making of other separable 'fastener parts including end stops and the like. It will also be understood '75 in this connection that the method herein disclosed for supporting and backing inserts within the impression chamber of dies in forming a die cast jacket or casing around the insert, and in relieving such supporting and backing pins by the pressure of the casting material is applicable to the formation of devices of any kind or class, and especially where it is desirable to apply the cast material to the entire exterior surface of the insert employed.

Upon a consideration of Figs. 1 and 4, especially, it will be seen that the pins 28, 28a employed are of elliptical form to fit into correspondingly formed recesses. While the pins of the units 41, "a are shown as being round, elliptical pins may here also be employed. The purpose of the elliptical formation is simply to provide support for the insert against twisting movement, or any other irregular contour may be provided which would accomplish this same result. This contour in the pins is important, especially where a core pin is not employed and where the centering lining and relief pins such as 28, 2841 alone would be employed.

In some forms of our invention and in the manufacture of certain cast parts, the inserts may be arranged in spaced relation to each other within a complete casting. These different forms and applications of our invention are not specifically shown and described in detail, as they are quite apparent from the disclosure in the several forms of construction hereindisclosed.

In connection with the formation of stringers with the coupling links or scoops thereon, it is not essential that the insert be first attached to the tape or stringer, as in some cases, it may be practical and desirable to form the links independently of the tape with the inserts contained within the coating or jacket of cellulose acetate or other material, in which event, the forked ends lla of resulting links as seen in Fig. 4 of the drawings will be normally separated to permit mounting of the beaded edge It, and then crimped or pinched thereon in the well known manner of attaching preformed metallic links to stringer tapes.

The cast material, such for example as cellulose acetate when employed will be heated and injected through the respective nozzles in accordance with the general teachings disclosed in our' prior application, Serial Number 746,771, filed October 4, 1934, of which this application constitutes a continuation in part.

The invention herein disclosed not only includes the novel method of forming die cast de-' vices from thermoplastic or similar die casting material upon an insert but also in the novel structural arrangement of dies, and particularly, in the use of the pins 2Q, 28a and the corresponding units 41, "a which may well be termed supplemental die parts which are yieldably supported in the dies andwhich when moved outwardly by the pressure of the casting material into the position such as illustrated in Fig. 9 of the drawings complete the formation of the impresslon in the die, or in other words, form part of the outer wall structure of the impression.

Where core .pins are used, as indicated in Figs. 5, 6, 10 and 11, the apertures or recesses left by these core pins may, if desired, be filled or partially filled with some of the casting material.

Having fully described our invention, what we claim as new and desire to secure by Letters Patent is:

1. In separable fasteners employing coupling links spaced longitudinally of a mounting member, each link comprising'a forked mounting end portion arranged on the mounting member and a coupling end portion projecting beyond one edge of the mounting member, said link comprising a die cast thermoplastic body, a metallic body arranged within and substantially completely enveloped by said thermoplastic body, the

metallic bo'dy forming means to securely retain the thermoplastic body on said mounting member, and said metallic body closely conforming to'the external contour of said link throughout saidmounting and coupling end portions thereof.

2. In a device of the character described, an elongated fabric mounting, member, a plurality of die cast metallic bodies fixedly secured to the mounting member at longitudinally spaced intervals thereon, an outer die cast thermoplastic body on each of said metallic bodies, the thermoplastic body forming a shell of predetermined thickness substantially completely enveloping the metal body and closely conforming to the contour of said metal body, and said metal body forming means. securely retaining the thermoplastic bodies against displacement from or movement longitudinally of said mounting member.

3. In separable fastener devices, a die cast thermoplastic fastener part having a predetermined surface contour, a die cast metallic insert arranged within said part and closely conforming in contour to'the contour of the external surface of said thermoplastic part throughout substantially the entire extent of said surface, said metallic insert having detents on predetermined surfaces thereof, and the thermoplastic,

body having integral portions extending into the detents of the metallic insert.

4. In separable fastener devices, a die cast ythermoplastic fastener part having a predetermined surface contour, a die cast metallic insert arranged within said part and closely conforming in contour to the contour of the external surface of said thermoplastic part throughout substantially the entire extent of said surface,

said metallic insert having detents on predeter-- mined surfaces thereof, the thermoplastic body having integral portions extending into the detents of themetallic insert, and a portion of the die cast insert being exposed through one surface of said thermoplastic body.

LOUIS H. MORIN. DAVIS MARINSKY. 

